Fuel cells are devices that generate electric current through chemical reactions. To put it better, a fuel cell uses chemical energy of hydrogen (or another fuel) to produce electricity in a clean and efficient manner. Its only products are electricity, heat, and water, and hence it is clean.
There are a wide range of applications for which fuel cells can be used. This includes transportation, emergency power back up, material handling etc. compared to other technologies, fuel cells have many advantages. They are more efficient, and have lower emissions. That is, they do not emit dangerous substances like carbon dioxide or air pollutants, as their only products are water and heat. Yet another advantage is that fuel cells operate in a silent manner.
The history of fuel cells began with the Welsh physicist Sir William Grove. In 1839, he demonstrated the first crude fuel cells. Although many people have tried to work on the concept of converting chemical energy into electric power, most of them were unsuccessful due to lack of resources.
The first successful fuel cell was developed by the British engineer Francis Bacon in 1932, using hydrogen, oxygen, an alkaline electrolyte and nickel electrodes.